remove annoying "unknown error" dialog. b=131399, r=dougt, sr=bienvenu, a=asa

docshell/base/appstrings.properties

@@ -28,4 +28,3 @@ repost=The page you are trying to view contains POSTDATA that has expired from c
 repostConfirm=The page you are trying to view contains POSTDATA. If you resend the data, any action the form carried out (such as a search or online purchase) will be repeated. To resend the data, click OK. Otherwise, click Cancel.
 unknownSocketType=This document cannot be displayed unless you install the Personal Security Manager (PSM). Download and install PSM and try again, or contact your system administrator.
 netReset=The document contains no data.
-unknownError=An unknown error occured while attempting to load the requested page.

docshell/base/nsWebShell.cpp

@@ -1029,11 +1029,6 @@ nsresult nsWebShell::EndPageLoad(nsIWebProgress *aProgress,
           // before we could read any data from it
           errorStr = "netReset";
           break;
-        case NS_BINDING_ABORTED:
-          break;
-        default:
-          errorStr = "unknownError";
-          break;
       }
       if (errorStr) {
         nsCOMPtr<nsIPrompt> prompter;